Autoimmune diseases, more than eighty of which have been identified, cause significant morbidity and disability and are notoriously difficult to diagnose. As many as twenty-four million Americans suffer from autoimmune disease, and treatment costs exceed $100 billion annually.
Recently, a new population of effector cells, TH17 cells, has been identified and implicated in various immune-related conditions. The discovery of these cells has had a major impact on the understanding of immune processes not readily explained by the TH1/TH2 paradigm. Importantly, TH17 cells have been associated with the pathogenesis of human autoimmune diseases including multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease, and psoriasis.
Further understanding of the differentiation, expansion, and function of TH17 cells in human cells, in association with rodent models, and a method for specifically identifying TH17 cells remain important goals in the exploration of autoimmune and other human diseases.